when i run my mpi application specifying the whole path to mpirun, it works fine.

jean:$ /home/jean/openmpisof/bin/mpirun mympi

however if I do:
jean:$ mpirun mympi

I get:

################
bash: orted: command not found
--------------------------------------------------------------------------
A daemon (pid 8464) died unexpectedly with status 127 while attempting
to launch so we are aborting.

There may be more information reported by the environment (see above).

This may be because the daemon was unable to find all the needed shared
libraries on the remote node. You may set your LD_LIBRARY_PATH to have the
location of the shared libraries on the remote nodes and this will
automatically be forwarded to the remote nodes.
--------------------------------------------------------------------------
--------------------------------------------------------------------------
mpirun noticed that the job aborted, but has no info as to the process
that caused that situation.
--------------------------------------------------------------------------
mpirun: clean termination accomplished